Releasable fingers for offset presses



HELEASABLE FINGERS FOR OFFSET PRESSES.

APPLICATION FILED APR, 1. 1921.

1,42%260, Patented Aug. 1, 1922.

3 SHEETS-SHEET I m I I| l Q l@ fiwefifari- FWQmZ'FKL'CM E F. F. RICHARDS.

RELEASABLE FINGERS FOR OFFSET PRESSES.

APPLICATION FILED APR. 1. 1921.

11,424,260, 7 Patented Aug. 1, 1922.

3 SHEETS-SHEET 2- s.--- 2631: l' I' 23 l T l| I 4 2 i [@T 1 ||m|-| 1 21 I 19 17 v F. FfRlCHARDS. RELEASABLE FINGERS FOR OFFSET PRESSES.

APPLICATION FILED APR. 1, 192i.

1 A24 Patented Aug. 1, 1922.

3 SHEETS-SHEET 3.

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FRANK F.

., w i I i v" r H Y w ar RICHARDS, 0 ST. PAUL, ILEINNESOTA, ASSIGNOR TO BROVIN & BIG-ELOW', 0

S1. PAUL, MINNESOTA, A COBPQRATION OF MINNESOTA.

RELEASABLE FINGERS FOR OFFSET PRESSES.

t ,4t24t,26 0.

Application filed April 1,

1 0 all whom it may concern:

Be it known that I, FRANK F. RICHARDS, a citizen of the United States, residing at tit. Paul, in the county of Ramsey and State of Minnesota, have invented a new and useful Improvement in Releasable Fingers for Offset Presses, of which the following is a specification.

This invention relates to releasable guide lingers which are adapted to be associated with the stops on automatic offset presses, the primary object of which is to prevent streaking the printed sheets passing through the offset press. in the operation of an offset press it is sometimes desirable to pass the sheets from one press to another where a different color ink is applied and before the first ink is dried, in this case with the stationary fingers on offset presses used heretofore the fingers drag over the sheets, having a tendency to streak the same in a very undesirable manner. Naturally, if the .ink is not entirely dry some of it will be collected by the fingers and sufficient of the ink pile up on the fingers to badly streak the sheets. My invention includes means for automatically releasing the lingers at the proper time so as to space them away from. the sheets as the sheets pass through the press from the feed table to the cylinder. This invention further includes guide fingers which cooperate with the rel(- .a. -atble lingers which are also movable so as to prevent streaking of; the sheets passing through the offset press. lleretofore the guide finrs, which are associated with the cylinder, were stationary and were very apt to streak the sheets passing through the press if they had a tendency at all to drag over the printed surface. The guide fingers are positioned adjacent the cylinder in the usual manner so that they will cooperate with the sheet gripping mechanism on the cylinder to insure the gripping of the sheets at the proper time, but are released or raised automatically into a position away from the printed surface of the sheets so as to prevent dragging or streaking the sheets.

My invention also includes adjustable means for timing the released position of the fingers associated with the stops on the feed table so that they can be adjusted for Specification of Letters Patent.

Patented Aug. it, 1922.

1921. Serial No. 457,635.

long or short sheets. This detail of the in vention is essential, as the sheets pass rapidly through the offset press and it is necessary that the fingers cooperate with the stops to prevent the sheets from being fed to the cylinder only at the proper time The fingers are released at the moment that the feed cams on the feed table are brought into operation to feed the sheets from the table to the cylinder. The releasable fingers allow thick or thin sheets to be run through the offset press without any danger of streakin g the ink on the same.

In the drawings forming a part of the specification:

Figure 1 is a diagrammatic detail cross sectional view in side elevation of a portion of the feed table and cylinder of an, offset press, ilhistrating the releasable and guide fingers with their cooperating parts.

Figure 2 is a side sectional elevation of a detail portion of the feeding table of an offset press, illustrating my invention assoelated with the stop fingers of the same.

Figure 3 a detail plan view of the parts illustrated in Figure 2.

Figure 4 is a plan view of a detail portion of the cylinder and guide fingers.

in the drawing the feed table A, only a portion. of which is illustrated, is of the or dinary cmistruction having the wooden rollers 10 on the bed of the same, such as are used in the automatic offset presses of well known construction. In the OpGLtti-lOD of an :ultoinatic offset press the sheets ll which are to be printed are stacked at the receiving end of the feed table and are lifted individually by air and started on to the roll ers ll) of the feed table A, the receiving end of the offset press not being illustrated in my drawings as all this is of well known ordinary construction.

The sheets 11 to be printed on the offset press are fed on to the feed table A and just before being passed to the impression cylinder B they are held momentarily while a sheet is being printed which is held on the impression cylinder B in the ordinary well knownv manner. The forward edge of the sheet 11 passes over the plate 12 of the feed table A and is engaged by the fingers 13, as illustrated in Figure 2, the fingers 13 being positioned below the plate 12 and their free end 14 which is bent upward being adapted to extend through the recesses or notches 15 in the plate 12 so as to engage the forward edge of the sheet 11. The fingers 13 are mounted 0.11 a transversally extending shaft 16 which is rotated at the proper time to position the fingers 13 into engagement with the forward edge of the sheet 11. fleretofore guide fingers which were held stationary have been positioned directly above the notches 15 to prevent the sheetssuch as 11 from passing over the ends 14: of the fingers 13.. My invention includes the feed table guide fingers 17 which are adjustably held on the transversally extending shaft 18 by the set screw 19 so that they can be adjusted in a rotary direction or longitudinally on the shaft. These fingers 17 are adapted to move into contact with the ends 1 1 of the fingers 13 at the time the fingers 13 move into position to stop the sheet 11 on the feed table A.

Thefingers 17 are connected to the shaft 1S. The shaft 18 extends trausversally across and above the feed table A, being j ournaled in suitable brackets on either side of the same and is adapted to be rotated by thecam 20 which is secured to the transversally extending shaft 21, which engages the operating end of the lever 22 in a manner to rotate the shaft 18 and oscillate or elevate the free ends of the fingers 17 at the proper time. The lever arm 22 is rigidly secured on one end=to the shaft 18 by a set screw 23. The cam 20 is formed with an extendable portion 24 which is held by the bolts 25 so that the face of the cam can be extended or contracted to vary the length of time of holding the free ends of the fingers 17 out of engagementwith the stop fingers 13. This is to facilitate the timing of the fingers 1'? in accordance with long or short sheets pass ing through the offset press. A stopping arm 26 which is adjiiistably mounted on the bracket 27 limits the movement of the operating arm 22 in one direction, while a coil spring 28 tends to draw the arm 22 toward and against the stop 26. The stop 26 is adapted to set the fingers 17 so as to engage the stop fingers 13 with more or less pressure. The fingers 17 are formed of spring material.

When the finger 13 is moved into position, as illustrated in Figure 1 out of the path of the sheet 11 the finger 17 is moved into the position illustrated in the same figure, so that its free endis entirely free from the sheet 11, allowing the sheet 11 to be engaged by the feed cams 30, which are of ordinary construction, to feed the sheet 11 to the grippers 31 on the cylinder B. At this moment the grippers 31 are in open position ready to receive the forward end of the sheetll and are operated by a lever arm 32, the free end of which engages the cam only a portion of which is illustrated. This cylinder gripping mechanism is of ordinary well known construction.

Asecond set of guide fingers 34 are adjustably mounted on the transversally extending shaft 35, but are held rigidly to the shaft 35 by the set screws 36. The outer end 37 of the fingers 3st is curved upwardly so as to freely admit the sheet 11 beneath the same, while the inner end 38 is flat and elongated so as to extend in close position to the surface of the cylinder B to insure guiding the forward end of sheet 11 into position to be engaged by the grippers 31.

After the grippers 31 have engaged the sheet 11 the guide fingers 34L are elevated by the operating arm to, the free end of which engages the cam l1 mounted on the cylinder B. The inner end of the arm 40 mounted on the transversally extending shaft l2'and the shaft 35 is held by a pair of arms 13, only one of which is illustrated in the drawings, one end of which is secured to the shaft and the other end being connected to the shaft' l2. By means of a pair of hangers at at either end of the shaft 35 the fingers 3st are held away from the cylinder 13, these hangers freely engage the shaft 35 at either end and limit its move in one direction. The

lower ends of the hangers 44 are formed with a hook 45 which engages the shaft 35 so that it can be easily removed or lifted out of engagement with the hanger when it is desired. The operation of the cam 41 is not sufficient to raise the shaft 35 out of the hook ends of the hangers 4 1.

The cam 11 is secured to the end of the cylinder B and is formed with a cut-away portion which releases the lever 40 at the proper time to bring the fingers 34 into close relation to the cylinder at the time that the grippers 31 come into operation to grip the sheet 11. After the sheet 11 is gripped by the grippers 31 the guide fingers as are elevated away from the surface of the same to prevent streaking or marking the inked surface of the sheet.

Both the guide fingers 17 on. the feed table and the guide fingers 34 associated with the cylinder are adapted to operate in unison with the parts of the offset press which operates rapidly to pass the sheets from the feed table to the cylinder where they are printed. Both sets of guide fingers are automatically released into a position away from the printed surface of the sheets. This construction allows thick or thin sheets to be used in an offset press without any danger of streaking or marking the printerairface of the same. These automatically releasable guide fingers save considerable time in the operation of an offset press in makeready of the press and eliminates entirely the streaking by the fingers on the sheets, a feature which has been heretofore very diificult to adjust, yet the operation and construction of my invention is simple, inexpensive and practical.

Having described my invention, what I claim as new and desire to protect by Letters Patent is:

1. The combination of an offset press adapted to print different colors unto sheets from cylinders having a feeding table including a series of guide fingers associated with the stops on said feeding table and a series of guide fingers associated with the impression cylinder and means for automatically releasing said guide fingers out of the path of the sheets passing through said press to prevent streaking the printed side of the same.

2. The combination of an offset press having a sheet feeding table and an impression cylinder, sheet gripping means associated with said cylinder, sheet stoppingmeans associated with. said feeding table and a series of automatically releasable guide fingers associated with said stopping means on said table, and with said gripping means on said cylinder, whereby said guide fingers are re leased out of the path of travel of sheets passing through said offset press to prevent streaking of the sheets by said guide fingers.

3. An automatic offset press including a sheet feeding table, sheet stop means associated with said table, an impression cylinder, sheet gripping means on said cylinder, a series of guide fingers associated with said gripping means, a series of guide fingers associated with said sheet stopping means, means adapted to position said guide fingers in close proximity to the surface of said impression cylinder and gripping means momentarily and to elevate these guide fingers away from the sheet after it is gripped by said impression cylinder and means for releasing the guide fingers out of the path of the sheet on the feeding table when said stops are released and the sheet is passed to the impression cylinder.

4;. An automatic offset press including a sheet gripping means on the impression cylinder, a sheet feeding table adjacent the impression cylinder, sheet stopping means on said feeding table, a series of guide fingers associated with said stopping and gripping means and means for automatically releasing said fingers out of operating position to prevent streaking of the sheet passing through the offset press on its printed face.

to guide a sheet into said gripping means and means for releasing said guide fingers at the moment said gripping means has engaged a sheet to raise said fingers away from the printed surface of the sheet carried by the impression cylinder.

7. An automatic offset press, comprising an impression cylinder, a sheet feeding table adjacent said impression cylinder, sheet feeding cams at the discharge end of said sheetfeeding table, a series of stop fingers adjacent said cams, a series of guide fingers adapted to cooperate with said stop fingers and means for automatically releasing said stop and guide fingers simultaneously with the operation of said feeding cams, whereby a sheet is fed from said table to said impression cylinder without marring the printed surface thereof.

8. An automatic offset press having an impression cylinder and a feeding table adjacent thereto, two sets of guide fingers, one of which is associated with the stops on said feeding table, and the other set being associated with the sheet gripping means on said cylinder and means for releasing the first set of guide fingers while the sheet is being fed to the impression cylinder and means for releasing the second set of fingers after the sheet has been gripped by the impression cylinder to prevent streaking of the ink on the sheet passing through said press.

9. Autoi'natically releasable guide fingers in combination with an automatic offset press, including means for holding the [ingers in operating position against the stops on the feed table of said press momentarily and for holding said guide fingers momentarily adjacent the gripping means on the impression cylinder of said offset press for the purposesspecified.

FRANK F. RICHARDS. 

